Sudden Death Syndrome (SDS) is caused by the fungus, Fusarium virguliforme. The life cycle of SDS is denoted by two distinct periods of infection of soybean roots in the early spring, followed by advanced disease development during flowering. SDS infects soybeans in the spring under the cool, wet soil conditions that are often associated with early planting.

Chlorotic leaves and interveinal necrosis on soybean does not always equal Sudden Death Syndrome (SDS). Diagnosing sudden death syndrome of soybeans (SDS) based solely on foliar symptoms can lead to an incorrect diagnosis as a few other pathogens can result in SDS-like symptoms.

Symptoms of SDS are showing up in a few areas. Initial symptoms include yellow spots between the leaf veins that coalesce into large areas of interveinal chlorosis and necrosis.